A Levels Chemistry

Monopotassium citrate is used as an emulsifying agent in powdered milk and in powdered soups.
It may be represented by the formula shown.
CH,CO,H
HO-C-Co, K*
ČH,CO,H
Which statements about monopotassium citrate are correct?
1
It can form optical isomers.
2
It can act as a dibasic acid.
3
It can form esters with both acids and alcohols.


Choice C is correct because: 

Statement 1 is incorrect

Monopotassium citrate cannot form optical isomers. Optical isomers occur when a molecule has a chiral centre, which is a carbon atom with four different groups attached. In the case of monopotassium citrate, there is no chiral centre present.

Statement 2 is correct

Monopotassium citrate can act as a dibasic acid since it has two acidic protons (-CO2H groups) that can be donated in a reaction. 

Statement 3 is correct

Monopotassium citrate can also form esters with both acids and alcohols since it has both a carboxylic acid (-CO2H) & an alcohol (-OH) functional group. 

Choices A, B & D are incorrect because they do not state the fact that only statements 2 & 3 are correct.

An Introduction to Organic Chemistry | 2007 - O/N - 9701/1 | Q40